Electric motor



(No Model.)

Witness 6 s A. D. BLODGETT & J. P. TIRRELL,

ELECTRIC MOTOR.

Patented Nov. 25, 1884.

int/e 711 /0235,-

M at;

UNITED STATES PATENT Orrrcs.

AARON D. BLODGETT AND JACOB P. TIRRELL, OF BOSTON, MASS, ASSIGNOBS TO THE ELECTRIC SIGNAL CLOCK COMPANY, OF MASSACHUSETTS.

ELECTRIC MOTOR.

.iPECIFL-UATEGN forming part of Letters Patent 1330. 308,5d8, dated November 25, 1884. Application filed August 16, 1882. (No model.)

To to whom, it may concern: its poles abut against a stop, J, of diamagnetic Be it known that we, AARON D. BLO'DGETT materiahattached to the armature. This moveand J A0013 1 TIRRELL, of Boston, in the ment causes the dog H to rotate the ratchet a county of Suffolk and State of Massachusetts, distance equal to one tooth of the latter. 5 have invented certain Improvements in Elec- \Vhen the circuit through the magnet is brotric Motors, of which the following is a speci ken. a retracting-spring, K, arranged in any fica-tion. suitable manner,swings the magnet away from This invention has for its object to increase the stop J against a backstop, L. The spring the power and efficiency as a motor of an elec- K is in this i'orm shown in Figs. 1 and 2 at- 10 tro-magnet which is excited intermittently tached to the dog Hand to the supportingand caused,when excited, to give motion toa base, and serves both to retract the magnet pawl or dog engaging with the teeth of a and to press the dog H against the ratchet. ratchet-wheel, said pawl or dog being thus The armature B presents aconcave surface to moved intermittently and caused to rotate the the poles of the electroanagnet, which surface 15 ratchet-wheel and drive the connected mechis approximately but not absolutely parallel anism step by step. with the path or are in which the poles of the Of the accompanying drawings, forming a magnet move when the magnet oscillates, the part of this specification, Figure 1 represents armature being somewhat eccentric to the are i a plan view of an electro-maguet and its an in which the poles'of the magnet move, so that 20 mature embodying our invention, the magnet the poles of the magnet are closer to the arbeing adapted to operate a single pawl. Fig. mature when the magnet is excited, and thus 2 represents an end view of the same. Fig. 3 drawn to the stop J, than when the circuit is represents a plan view showing the magnet broken and the magnet retracted. This form adapted to operate two pawls alternately. and arrangement of the armature locates it 2" The same letters of reference indicate the always comparatively near the poles of the same parts in all the figures. magnet, even when thelatter is retracted, and

In carrying out our invention we pivot an at the same time causes the poles of the magordinary electro-magnet, A, to a base or supnet, in seeaing the nearest point of approach 4 port, so that said magnet can oscillate in a to the armature, to move through an extended 3o horizontal plane, and secure rigidly to said are, and thus require a considerable momensupport a soltiron armature, B, so arranged tum, which materially increases the force of So that the poles or cores of the magnet can apthe dog H and makes its action more positive proach and recede from it when the magnet and effective. The steps J and L limit the oscillates on its pivot. \Ve prefer to pivot vibrations of themagnct andpreventthepoles 3 the electro-magnet by a pivot-pin, C, passing thereof from passing away from the armature through ears on a post, D, on the base F, and in either direction. 8 5

through an arm, G, rigidly attached to the In Fig. 3 we have shown an arrangement electro-magnet, said arm being thus pivoted whereby the magnet, instead of being sud to the post 1). To the outer end of the arm denly arrested by a stop in its motion toward 0 G is pivoted a dog, H,which engages with the the armature, is allowed to move beyond the r 4 teeth of a ratchet, I, said ratchet giving mopoint of nearest approach to the armature, 0

tion to any suitable mechanism or apparatus and as it passes said point to break the circuit for example, the rotating time-cylinder shown through the magnet, and as it moves onward in Letters Patent of the United States granted to operate a second dog or pawl, H, the force to George XV. Blodgett and Aaron D. Blodgrequired to arrest the magnet being thus utilett, August 1, 1882. \Vhen the magnet is exized. In this instance the arm G- of the mag- 5 cited, the magnetic force exerted on the arnet is pivoted, as before, and is provided with mature causes the magnet to swing in the (lia forked end, one part of which has the dog rection indicated by the arrow in Fig. luntil H,- while the other is pivoted to one end of a lever, P, which is pivoted centrally to a fixed support and has pivoted to its other end the dog H. The proximate surface of the arma ture is composed of two curves, each diverging slightly from the center of the armature to the ends thereof from the are described by the poles of the magnet. XVhen the magnet reaches the center of the armature, it reaches the point of nearest approach, and gradually separates from the armature in moving in either direction from the center.

R represents a circuit-closing disk connected with one pole of a battery, (the other pole of which is connected with the arm G and having a projection, S. Said disk is rotated at a definite rate by any suitable means.

T U represent metallic springs arranged to make contact with the projection S once during each rotation of the disk It. and connected by wires V V with springs \V X, which are arranged at opposite sides of the arm G of the magnet. Said arm G has at one side aninsulated metal block, a, connected by a wire with the helices ol the magnet. The spring \V is arranged to bear against the block a after the magnet, when moving in the direction indieated by the arrow in Fig. 3, has passed the center of the armature. The spring X is arranged to bear against the arm G after the magnet, when moving in the opposite direc tion, has passed the center of the armature.

The operation is as follows: Suppose the magnet to be at one extreme of its movement and the block a bearing against the spring \V, when the projection S meets the spring T, the circuit is closed and the magnet is excited and caused to move toward the eenterot' the armature. Just before the magnet reaches the center of the armature the spring \V separates from the block a and the circuit is broken. The armature continues its movement, meeting the spring X and passing to the other end of the armature, and remains there in contact with the spring X. until the projection S meets the spring U, when the circuitis again closed and the magnet caused to approach the center of the armature, separating from the springX and-agai 11 breaking the circuit as it approaches the center of the armature, and again passing over to the spring \V. 'lhemagnet is thus allowed to oscillate through a long are, each movement causing one of the dogs to rotate the ratchet and the other to dlaw back to a succeeding tooth.

In Fig. l we have shown a device to retard the movement of the magnet when it is being retracted by its retraetingspring, said device being composed of a cylinder, a, pivoted at I), and open at one end, and a piston, 0, working in said cylinder,and attached to the end of a rod, (1, which is pivoted at e to the arm G of the magnet. The piston c has an orifice, f, with a valve, g, which closes said orifice when the piston is moved outwardly in the cylinder, and confines the air in said cylinder, thereby causing the piston to move slowly and retard the retracting movement of the magnet, as will be readily seen. The valve opens when the piston is moved inwardly by the opposite movement of the magnet, so that the piston and cylinder offer no resistance to said movement.

\Ve claim- 1. The combination, with a pawl and a ratchet engaged thereby, of an operating device composed of a pivoted electro-magnet, intermediate connections between said magnet and pawl,whereby the magnet is caused to increase the force or momentum of the pawl, and a fixed armature arranged, substantially as described, with relation to the poles of the magnet, as and for the purpose set forth.

2. The combination of a pivoted electromagnet having a curved surface arranged eccentrically, as described, with relation to the are described by the poles of the magnet, and stops limiting the vibrations of the magnet and preventing the same from passing a way from the armature in either direction, as set forth.

The combination of a pivoted electromagnet, two dogs or operating devices carried thereby and adapted to operate alternately, a fixed elongated armature, and automatic devices for breaking and closing the circuit through said magnet while it is in motion, as Set forth.

4-. In combination with a pivoted electromagnet, the hereindescribed segmental armature supported by a single centrally-located screw, and adapted to be adjusted thereon to any desired angle with respect to the path of the pivotedmagnet, substantial] 'as described.

The combination, with the pivoted electro-magnet and suitable pawl and ratchet operated by the oscillations thereof, of the herein described segmental armature provided with an adjustable supporting screw and adapted to be set at any desired angle with respect to the are described by the poles of the magnet, and thereby aliord increased attraction at the desired point, substantially as set forth.

In testimony whereof we have signed our names to this specification, in the presence ot' two subscribing witnesses, this 14th day 01 August, 1882.

AARON D. BLODGET". JACOB P. TIRE-ELL. \Vitnesses:

O. F. BROWN, A. L. WHITE.

ICO 

